A method and a device for controlling an internal combustion engine having an exhaust-gas after-treatment system is discussed in German Patent Application No. 199 06 287. In the system described therein, a particle filter may be used which filters out particles contained in the exhaust gas. In order to accurately control the internal combustion engine and the exhaust-gas after-treatment system, the state of the exhaust-gas after-treatment system may need to be known. Sensors, among other devices, may be used to determine the state of the exhaust-gas after-treatment system. Sensors may be used in particular to provide the temperature values which characterize the temperature upstream from, downstream from, and/or in the exhaust-gas after-treatment system.